Description of the Prior Art
This invention, in its preferred form, relates to speed controlling apparatus, and particularly to such apparatus as adapted to be mounted with respect to a motor boat, whereby the motor boat may be operated at very low rates of speed.
The prior art has recognized the desirability of operating motor boats at relatively slow speeds to facilitate trolling, whereby a fishing line is drawn slowly through the water to attract desired species of fish. Most motors used to propel fishing or recreational boats are gas-type motors that are designed to operate at a single rate of speed. Such gasoline motors are not typically associated with speed changing mechanisms such as would be provided by a set of gears. Rather, speed control is obtained by manipulating the fuel throttle of the boat's motor.
A problem arises when it is desired to operate such motors at a very slow speed, even slower than the minimum or idle speed of the boat's motor. To this end, the prior art as illustrated by U.S. Pat. Nos. 1,576,237 of Dawson; 1,799,455 of Cavert; 2,719,503 of Smith; 2,998,795 of Downie et al.; and 4,026,231 Fedorko, has disclosed speed changing apparatus taking the form of a plate typically known as a trolling plate that is disposed in a position immediately behind the motor's propeller and transverse to its wash. The disposition of a trolling plate to confront the propeller's wash significantly reduces the effectiveness of the motor to propel the boat, whereby the motor may operate at speeds in access of its idling speed and yet move the boat at the desired relatively low or trolling speeds.
The above referenced Dawson patent discloses an attachment for boats that mounts a trolling plate in a variety of positions between a fully vertical position and a fully horizontal position. A plurality of apertures are disposed to receive an adjustable screw, whereby the position of the trolling plate may be locked in each of a plurality of positions corresponding to the apertures.
The above referenced Fedorko patent discloses a hydraulic mechanism, whereby its trolling plate may be disposed from a fully vertical position through a series of infinite intermediate positions to a fully horizontal position. The hydraulic mechanism includes a motor, whereby a piston is rectilinearly driven to thereby reposition the trolling plate as desired. Suitable valve mechanisms are provided, such that when the hydraulic pump is deactuated, the fluid directed to the hydraulic mechanism is trapped, whereby the trolling plate is locked in position.
The prior art has recognized several problems as yet unsolved, related to the use of such trolling plates. First, trolling plates of the prior art are particularly adapted to be used with a particular boat and/or outboard motor and are not readily adapted to be used with a variety of boats, motors and/or propellers of varying size, thus preventing the transfer of such a trolling plate and its mounting mechanism from one motor or boat to the next. Further, it is contemplated that an outboard motor may be used with propellers of varying size, thus requiring an adjustment of the size and/or position of the trolling plate, such adjustment not now being provided by the teachings of the prior art.
A further unsolved problem of the prior art relates to the difficulty in controlling a boat when subject to even modest wind conditions, and in particular when the wind is directed across the sides of the boat. Under such conditions, the boat is blown side ways, such loss of control being particularly aggravated when the boat is being propelled at very slow speeds, i.e. when used with a trolling plate. A related problem appears when it is desired to steer the boat at very slow speeds as would be contemplated with the use of these trolling plates.